I just finished a little Christmas bookbinding project where I bound together some previous year's Christmas cards. I don't get very uptight about saving cards, but I also don't like to throw them away. Sometimes I will cut them up to make gift tags but there are always some with letters written inside or other reasons why I want to keep them. So I decided to make a book, at least it will be easier to keep them in this format! They are just sewn onto the ribbons with a layer of PVA on the spine.
Let me know if you have other creative uses for old greeting cards! And have a Merry Christmas and a happy holiday too!